Highly flexible and transparent self-healing elastomer based on localized supramolecular interactions with enhanced mechanical properties and long-term storage stability

This study prepared a highly flexible and transparent self-healing elastomer with enhanced mechanical properties and long-term storage stability, facilitated by localized supramolecular interactions. By incorporating a functional oligomer containing localized urea groups into a conventional elastomeric matrix, increased supramolecular interactions were promoted through multiple hydrogen bonds among clustered functional groups. The resulting supramolecular elastomers exhibited excellent optical properties, including total transmittance exceeding 90 %, yellow index less than 2, and haze under 1 %, along with elastic recovery of 40 %. Notably, the self-healing elastomer developed in this study effectively overcame the typical trade-off between mechanical and self-healing properties in conventional self-healing materials, achieving superior mechanical strengths compared to conventional elastomers and an outstanding self-healing efficiency of 94.0 % within a few minutes. Moreover, by tailoring the chemical structure of the oligomer, significant improvements in the long-term solution storage stability of the solution for urea systems were achieved. These results are attributed to the unique supramolecular network derived from multiple hydrogen bonding interactions among the localized functional groups in a confined zone. A mechanism for improved mechanical properties and outstanding self-healing performance is also proposed using a model system.